1. Field of the Invention
The present invention relates to a photoelectric switch device for detecting an object in a specified region of detection.
2. Description of Related Art
Typically, various photoelectric switch devices are widely used to detect an object in a specified region of detection in, for example, a manufacturing line in a factory. Such a photoelectric switch device projects light rays toward a specific field of detection in which an object is expected to be present and detects an object in the specific region of detection on the basis of a value relating to light rays reflected by the object. A conventional triangulation method is used for some of this kind of photoelectric switch devices. The triangulation type photoelectric switch device is also referred to as a distance setting type of photoelectric switch device. Reference is made to FIGS. 25 through 27A to 27C which show the structure and operation of one of the conventional triangulation type photoelectric switch devices for the purpose of providing a brief background that will enhance an understanding of the present invention.
Referring to FIG. 25, a triangulation type photoelectric switch device 800 comprises a light emitting diode 801 as a light source, a projection lens 802, a focusing lens 803 and a photoelectric position sensing device (PSD) 804. The light emitting diode 801 is coaxially aligned with the optical axis Xp of projection lens 802. The projecting lens 802 and the focusing lens 803 are arranged with a specified separation in the same vertical plane including the optical axis Xp of the light projection lens 802. The light projecting lens 802 directs light rays emanating from the light emitting diode 801 toward an object 900 located remotely from the photoelectric switch device 800 in the optical axis Xp of the light projection lens 802. The light rays are then reflected back by the object 900 and focused on the photoelectric position sensing device 804 by the focusing lens 803 to form a light spot on the photoelectric position sensing device 804.
The position of the light spot Lp on the photoelectric position sensing device 804 varies according to the distance of the object 900 from the photoelectric switch device 800, and more particularly to the photoelectric position sensing device 804. This distance is hereafter referred as switch-to-object distance. Specifically, the light spot Lp is formed at one of opposite ends, for example, an end e1, of the photoelectric position sensing device 804 when the object 900 is at the closest switch-to-object distance of a specified field of detection D0 and shifts in position towards another end e2 of the photoelectric position sensing device 804 as the object 900 moves away from the photoelectric switch device 800, i.e. as the switch-to-object distance increases.
The photoelectric position sensing device 804 generates two position signals N and F having levels according to positions of the light spot Lp formed thereon. Specifically, the position signal N has a photoelectric signal (current) level proportional to the distance of the light spot Lp from the end e1 of the photoelectric position sensing device 804. The position signal F has a photoelectric signal (current) level proportional to the distance of the light spot Lp from the other end e2 of the photoelectric position sensing device 804. Accordingly, the switch-to-object distance of the object 900 is found on the basis of these two position signals N and F.
The photoelectric switch device 800 has a specified field of detection or axial detectable region of detection D0 that is defined between the closest axial position P1 and the remotest axial position P2 which are axial limit positions for light rays incident upon the photoelectric position sensing device 804 through the focusing lens 803. The axial detectable region of detection D0 is divided into two sub-regions on both sides of a specific axial position ST that is variably preset, namely a front half axial region D1 that is on a side of the specific axial position ST close to the photoelectric switch device 800 and is used as an effective detection region and a rear half axial region D2 that is on a side remote from the photoelectric switch device 800 with respect to the specific axial position ST and is excluded from detection as an ineffective detection region.
The photoelectric switch device 800 is configured so as to detect an object 900 in the axial detectable region D0. However, the photoelectric switch device 800 determines that the object 900 is present within the effective detection region D1 only when light rays incident upon the photoelectric position sensing device 804 are from the object 900 positioned in the effective detection region D1.
Referring to FIGS. 26A and 26B showing a method of determining whether an object 900 is present within the effective detection region D1 on the basis of position signals N and F from the photoelectric position sensing device 804, a difference in level between N and F position signals (Nxe2x88x92F) represents an axial position of the object 900 within the axial detectable region D0 and can be used as a position signal. In practice, the position signal is expressed as a ratio of the position signal level difference (Nxe2x88x92F) relative to the total level of N and F position signals (N+F) for the purpose of normalization. The normalized position signal {(Nxe2x88x92F)/(N+F)} is examined with respect to a threshold value TH, which meets with the position signal relating to the specific axial position ST, to determine whether an object 900 is present within the effective detection region D1. That is, it is determined that an object 900 is present within the effective detection region D1 when the position signal {(Nxe2x88x92F)/(N+F)} is greater than the threshold value TH as shown in FIG. 26A or that an object 900 is not present within the effective detection region D1 but is within the ineffective detection region D2 when the position signal {(Nxe2x88x92F)/(N+F)} is smaller than the threshold value TH as shown in FIG. 26B. The threshold value TH may be varied to shift the limit axial position ST so as to change, expand or narrow, the effective detection region D1 and the ineffective detection region D2.
FIGS. 27A to 27C illustrates a process of presetting a threshold value TH in the prior art photoelectric switch device 800. The prior art photoelectric switch 800 is provided with a threshold value trimming dial 810, a detection indicator lamp 811 and a detection stability indicator lamp 812. As shown in FIG. 27A, after putting an object 900 at a specified axial position in the optical axis Xp of the photoelectric switch device 800 and powering on the photoelectric switch device 800 to project light rays to the object 900, the threshold value trimming dial 810 is continuously turned clockwise until the detection indicator lamp 811 turns on. Then, the threshold value trimming dial 810 is set to a position indicated by a reference numeral xe2x80x9c1xe2x80x9d. Subsequently, as shown in FIG. 27B, after removing the object 900 from the optical axis Xp which turns off the detection indicator lamp 811 and directs the light rays to a reflective reference object 901, the threshold value trimming dial 810 is further continuously turned clockwise until the detection indicator lamp 811 turns on again. The threshold value trimming dial 810 is set to a position indicated by a reference numeral xe2x80x9c3xe2x80x9d. If there is no reflective reference object 901, the threshold value trimming dial 810 is turned clockwise until it reaches an extreme position. Finally, as shown in FIG. 27C, the threshold value trimming dial 810 is turned back counterclockwise to a midpoint, namely a position indicated by a reference numeral xe2x80x9c2xe2x80x9d, between the positions xe2x80x9c1xe2x80x9d and xe2x80x9c3xe2x80x9d. As a result, a specific axial position ST is set up at a position midway between the object 900 and the reference object 901. In other words, a threshold value TH meeting with the specific axial position ST is established. In this state, it is examined that both detection indicator lamp 811 and detection stability indicator lamp 812 turn on while there is an object 900 present in the field of detection and that) while the detection stability indicator lamp 812 turns on, the detection indicator lamp 811 turns off when the object 900 is removed from the field of detection. If the detection stability indicator lamp 811 does not turn on during the threshold value setting process, this indicates that there is only a small margin between the position of the object 900 and the specific axial position ST and/or between the specific axial position ST and the position of the reference object 901. After resetting the object 900, the same threshold value setup process shown in FIGS. 27A to 27C is repeated.
In the prior art photoelectric switch 800, it is too troublesome for the user to turn the threshold value trimming dial 810 while observing both detection indicator lamp 811 and detection stability indicator lamp 811 in order to set and adjust a threshold value. As a result, it is difficult to precisely recognize the axial position ST and in consequence to achieve a fine adjustment in the threshold value. Further, it is difficult to judge the margin between the position of the object 900 and the specific axial position ST as well as the margin between the specific anal position ST and the position of the reference object 901.
It is an object of the present invention to provide a photoelectric switch device in which a user can adjust and recognize a value relating to the processing of a photoelectric signal relating to light which is reflected by an object and representative of a position of the object, easily and accurately.
The foregoing object of the present invention is achieved by a photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls including at least first and second walls adjacent to each other and in which at least photoelectric means for receiving light reflected by an object in the field of detection and providing a photoelectric signal having a level according to a value relating to the light representative of a position of the object relative to the photoelectric means is installed; processing means for processing the photoelectric signal from the photoelectric means; display means disposed on one of the walls for changeably displaying a plurality of values relating to the processing of the photoelectric signal; adjusting means disposed on the first wall for adjusting the value displayed on the display means; and selection means disposed on the second wall for selecting a desired one of the values which is to be displayed on the display means.
The photoelectric signal is provided by received light after being reflected by an object in the field of detection and processed by the processing means. A plurality of values relating to the processing of the photoelectric signal can be changeably displayed on the display means.
The user can select a desired one of a plurality of the values that is to be displayed on the display means by the selecting means and adjust the value displayed on the display means by the adjusting means in the processing means. In this instance, the adjusting means and the selecting means are disposed on different walls of the box casing so that the user is prevented from making wrong operations of these means.
According to another aspect of the present invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls including at least first and second walls adjacent to each other and in which at least photoelectric means for receiving light reflected by an object in the field of detection and providing a photoelectric signal having a level according to a value relating to the light representative of a position of the object relative to the photoelectric means is disposed; processing means for processing the photoelectric signal from the photoelectric means; display means disposed on one of the walls for displaying an adjustable value relating to the processing of the photoelectric signal thereon and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection; adjusting means disposed on the first wall for adjusting the adjustable value displayed on the display means; and fixing means disposed on the second wall for fling the adjusted value as a value relating to the processing of the photoelectric signal.
The photoelectric signal is provided by received light after being reflected by an object and processed by the processing means. An adjustable value relating to the processing of the photoelectric signal, which is used to detect the object within a specified region of acceptable positions in the field of detection, is displayed on the display means. In this instance, the adjusting means and the selecting means are disposed on different walls of the box casing, so that the user is prevented from making wrong operations of these means. Furthermore, the user can adjust the value while viewing it on the display means, so that adjusting the value relating to the processing of the photoelectric signal is easy and precise and recognition of the adjusted value is easy.
The display means may changeably display a plurality of values involving the processing of the photoelectric signal thereon. In this instance, the user can easily recognize the values involving the processing of the photoelectric signal on the display.
According to another aspect of the invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls including at least first and second walls adjacent to each other and in which at least photoelectric means for receiving light reflected by an object in the field of detection and providing a photoelectric signal having a level according to a value relating to the light representative of a position of the object relative to the photoelectric means is installed; processing means for processing the photoelectric signal from the photoelectric means; setting means disposed on the second wall for setting an adjustable value that is provided as a result of the processing of the photoelectric signal and is used to make a detection of the object within a specified region of acceptable positions in the field of detection as a value involving the processing of the photoelectric signal; display means disposed on one of the walls for displaying the adjustable value set by the setting means thereon; and adjusting means disposed on the first wall for adjusting the value displayed on the display means in the processing means.
With this photoelectric switch device, the photoelectric signal is provided br received light after being reflected by an object and processed by the processing means. An adjustable value relating to the processing of the photoelectric signal, which is used to detect the object within a specified region of acceptable positions in the field of detection, is displayed on the display means. In this instance, the adjusting means and the selecting means are disposed on different walls of the box casing, so that the user is prevented from making wrong operations of these means. The user can set an adjustable value, that is provided from the processing of the photoelectric signal and used to detect the object within a specified region of acceptable positions in the field of detection as a value involving the processing of the photoelectric signal by the setting means. The adjustable value that is set up is displayed on the display means, so that the user can adjust the value displayed on the display means. Because the adjusting means and the setting means are disposed on different walls of the box casing, the user is prevented from making wrong operations of these means. Furthermore, the user can adjust the adjustable value while viewing it on the display means, so that adjusting the adjustable value relating to the processing of the photoelectric signal is easy and precise and recognition of the adjusted value is simple.
The display means may changeably display a plurality of values involving the processing of the photoelectric signal thereon. In this instance, the user can easily recognize the plurality of values involving the processing of the photoelectric signal on the display. Further, the display means may be disposed on the first wall and displays the adjustable value wxpressed in figures. In this instance, the display means is disposed on the wall on which the adjusting means is disposed. Therefore, the user can adjust the adjustable value while viewing it on the display means, so that adjusting the adjustable value relating to the processing of the photoelectric signal is easier and precise and recognition of the adjusted value is also easier.
The processing means installed within the generally rectangular-parallelepiped box detects an object within a specified region of acceptable positions in the field of detection and transmits a data signal representative of a result of the detection to an external instrument through a output cable which extends out from the generally rectangular-parallelepiped box casing through one of the walls other than the second wall. In this instance, the data signal representative of the result of the detection is transmitted to the external instrument through the output cable. Because the output cable extends from a wall different from the wall on which the selecting means, fixing means or setting means is disposed, a large-sized selecting means, fixing means or setting means can be employed and, furthermore, the output cable does not interfere with operation of the selecting means, fixing means or setting means. The wall from which the output cable extends out may be formed, for example, as a tapered wall at a comer between the first and the second wall. In this arrangement, the output cable does not interfere with operation of the selecting means, fixing means or setting means.
The photoelectric switch device may further comprise the indication means disposed on the second wall of the box casing to indicate information relating to the detection. Because the indication means is disposed on the wall on which the selecting means, fixing means or setting means is disposed, any of the selecting means, fixing means or setting means can be operated while viewing information relating to the detection on the display means.
According to another aspect of the invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls including at least first and second walls; photoelectric means disposed within the generally rectangular-parallelepiped box casing for receiving light reflected by an object in the field of detection to generate a photoelectric signal according to received conditions of the light; display means disposed on one of the walls for changeably displaying a plurality of values generated on the basis of the photoelectric signal; selecting means disposed on the second wall for selecting a desired one of the values that is to be displayed on the display means; and adjusting means disposed on the first wall for adjusting the selected value displayed on the display means.
The photoelectric signal is provided by received light after being reflected by an object in the field of detection. A plurality of values generated on the basis of the photoelectric signal are changeably displayed on the display means. The user can select a desired one of the values that is to be displayed and adjust the value displayed on the display means by the adjusting means. In this instance, the user can adjust the value while viewing it on the display means, so that adjusting the value displayed on the display means is easy and precise, and recognition of the adjusted value is simple.
According to another aspect of the invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls including at least first and second walls; photoelectric means disposed within the generally rectangular-parallelepiped box casing for receiving light reflected by an object in the field of detection to generate a photoelectric signal according to received conditions of the light; processing means for processing the photoelectric signal from the photoelectric means; memory means for storing data of values generated on the basis of the photoelectric signal by the processing means; display means disposed on one of the walls for displaying an adjustable value relating to the processing of the photoelectric signal thereon and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection; adjusting means disposed on the first wall for adjusting the adjustable value displayed on the display means; and fixing means disposed on the second wall for fixing and entering the adjusted value as a reference value in the memory means.
The photoelectric signal is provided according to received light reflected by an object in the field of detection and processed by the processing means. Values generated by the processing means are stored in the memory means. An adjustable value relating to the processing of the photoelectric signal and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection is displayed on the display means. The user can adjust the adjustable value displayed on the display means by the adjusting means and stores the adjusted value as a reference value in the memory means. In this instance, since the adjusting means and the selecting means are disposed on different walls of the box casing, the user is prevented from erroniously operating these means. Furthermore, the user can adjust the adjustable value while viewing it on the display means, so that adjusting the adjustable value relating to the processing of the photoelectric signal is easy and precise and recognition of the adjusted value is simple.
The display means is capable of changeably displaying a plurality of values generated on the basis of the photoelectric signal. Therefore, the user can easily recognize the values generated on the basis of the photoelectric signal. The photoelectric switch device may further comprise selecting means disposed on the second wall for selecting a desired one of the values that is to be displayed on the display means. In this arrangement, the user will easily be able to select a desired one of the values to be displayed on the display means. In particular, the selecting means is disposed on a wall different from the wall on which the adjusting means is disposed, as a result of which, the user is prevented from errouneously operating the selecting means and the adjusting means. The fixing means and the selecting means may comprise a single operative member. This is always desirable in order to miniaturize the box casing even when employing a large size of combined selecting/fixing member and to achieve improved operability.
According to another aspect of the present invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls including at least first and second walls adjacent to each other and in which at least photoelectric means for receiving light reflected by an object in the field of detection to generate a photoelectric signal according to received conditions of the light is installed; processing means for processing the photoelectric signal from the photoelectric means; memory means for storing data of values generated on the basis of the photoelectric signal by the processing means; setting means disposed on the second wall for setting and entering an adjustable value that is generated from the processing of the photoelectric signal and used to make a detection of the object within a specified region of acceptable positions in the field of detection as a value involving the processing of the photoelectric signal; display means disposed on one of the walls for displaying the adjustable value stored in the memory means; and adjusting means disposed on the first wall for adjusting the adjustable value displayed on the display means.
The photoelectric signal is provided by received light after being reflected by an object in the field of detection and processed by the processing means. Values generated by the processing means are stored in the memory means. An adjustable value relating to the processing of the photoelectric signal and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection can be stored as a reference value in the memory by the setting means. The user can adjust the adjustable value displayed on the display means by the adjusting means. In this instance, the adjusting means and the selecting means are disposed on different walls of the box casing, so that the user is prevented from erroneously operating these means. Furthermore, the user can adjust the adjustable value while viewing it on the display means, so that adjusting the reference value that is to be stored in the memory means is easy and precise and recognition of the reference value is simple.
The display means can easily be capable of changeably displaying a plurality of values generated on the basis of the photoelectric signal, so that the user can easily recognize the values generated on the basis of the photoelectric signal on the display means. The photoelectric switch device may further comprise selecting means disposed on the second wall for selecting a desired one of the values that is to be displayed on the display means. In this instance, the user can select a desired one of the values to be displayed on the display means. In particular, because the selecting means is disposed on a wall different from the wall on which the adjusting means is disposed, the user is prevented from erroneously operating the selecting means and the adjusting means. The fixing means and the selecting means may be comprised into a single operative member, which is always desirable to miniaturize the box casing even when employing a large size of combined selecting/fixing member and to achieve improved operability.
Further, the display means is disposed on the first wall on which the adjusting means is disposed, so that the user can easily and precisely adjust the value while viewing it on the display means and recognition of the adjusted value is also easer.
The photoelectric switch device may further comprise light receiving means disposed on a third wall, other than the first and the second wall, for directing the light to the photoelectric means. In this instance, the adjusting means, selecting means or fixing means is disposed on a wall different from the wall on which the light receiving means, so that the box casing is miniaturized even when employing a large size of selecting means, fixing means or adjusting means and improved operability is achieved.
According to another aspect of the present invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls in which at least photoelectric for receiving light reflected by an object in the field of detection to generate a photoelectric signal according to received conditions of the light means is installed; processing means for processing the photoelectric signal from the photoelectric means; display means disposed on a first wall of the walls for displaying a value relating to the processing of the photoelectric signal; adjusting means disposed on the first wall of the generally rectangular-parallelepiped box casing for adjusting the adjustable value displayed on the display means in the processing means; and shielding means disposed between the first wall of the generally rectangular-parallelepiped box casing and the adjusting means for shielding an interior of the generally rectangular-parallelepiped box casing from ambient light and air.
The photoelectric switch device may further comprise selecting means disposed on a second wall for selecting one of a plurality of values relating to the processing of the photoelectric signal that is displayed on the display means, light source means for generating light installed in the generally rectangular-parallelepiped box casing, and optical means disposed on a third wall for directing the light toward the field of detection and directing light reflected from the field of detection toward the photoelectric means. The shielding means preferably comprises an annular ring member having an integral elastic thin wall member. The wall functions to unit the push button to the annular ring member into one member. The adjust means may comprise a push button disposed in a bole formed in one wall of the box casing.
The photoelectric signal is provided by received light after being reflected by an object in the field of detection and processed by the processing means. Values related to the processing of the photoelectric signal are displayed on the display means so the user can adjust an adjustable value displayed on the display means using the adjusting means. The display means and the adjusting means are disposed on the same wall, so that the user can easily and precisely adjust the value relating to the processing of the photoelectric signal while viewing it on the display means and easily recognize the adjusted value. Furthermore, the shielding means is disposed between the box casing and the adjusting means, so as to help make the box casing air tight.
According to another aspect of the present invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing which is defined by a plurality of walls which includes at least first and second walls opposite to each other and in which photoelectric means for receiving light reflected by an object in the field of detection and providing a photoelectric signal having a level according to a value relating to the light representative of a position of the object relative to the photoelectric means is installed; optical means disposed on the first wall for directing light from the field of detection to the photoelectric means; processing means for processing the photoelectric signal from the photoelectric means; and display means disposed on the second wall for displaying values relating to the processing of the photoelectric signal.
The photoelectric signal is provided by received light after being reflected by an object in the field of detection and processed by the processing means. A value relating to the processing of the photoelectric signal is displayed on the display means. In this instance, the optical means and the display means are disposed on opposite walls of the box casing, so that, even though the box casing is miniaturized, sufficient areas for installation of the optical means and display means are certainly provided. In consequence, the user can easily and precisely recognize a value relating to the processing of the photoelectric signal while viewing the value. This ensures a high accuracy of detection of an object
The photoelectric switch device may comprise adjusting means disposed on the second wall for adjusting the value that is displayed on the display means. Disposing the adjusting means and the display means on the same wall enables the user to easily and precisely adjust a value while viewing the value on the display means. The photoelectric switch device may comprise selection means disposed on one of the walls, except the first and the second wall, for selecting a desired one of the values that is to be displayed on the display means. In this instance, the display means changeably displays a plurality of values relating to the processing of the photoelectric signal. The user can select a desired one of the values relating to the processing of the photoelectric signal that is to be displayed on the display mean and adjust the value displayed on the display means through the processing means. In particular, the adjusting means and the selecting means are disposed on the same wall of the box casing, so that the user is prevented from erroneously operating these means.
The photoelectric switch device may further comprise adjusting means disposed on the second wall of the box casing for adjusting an adjustable value relating to the processing of the photoelectric signal and necessary in order to make a detection of the object within a specified region of acceptable positions in the field of detection that is displayed on the display means and fixing means disposed on one of the walls excepting the first and the second wall of the box casing for fixing the adjusted value as a value relating to the processing of the photoelectric signal. Since the adjustable value that is relating to the processing of the photoelectric signal and used to detect an object is displayed on the display means, the user can adjust the adjustable value displayed on the display means and fix the adjusted value as a value relating to the processing of the photoelectric signal. In particular, the adjusting means and the fixing means are disposed on the same wall of the box casing, so that the user is prevented from erroneously operating these means.
The photoelectric switch device may further comprise setting means disposed on one of the walls, except the first and the second wall, for setting up an adjustable value that is generated from the processing of the photoelectric signal and necessary to detect the object within a specified region of acceptable positions in the field of detection as a value relating to the processing of the photoelectric signal and adjusting means disposed on the second wall for adjusting the adjustable value that is set up by the setting means and displayed on the display means through the processing means. In this instance, the user can set up an adjustable value that is generated from the processing of the photoelectric signal and necessary for making a detection of the object within a specified region of acceptable positions in the field of detection as a value relating to the processing of the photoelectric signal. The adjustable value set up by the setting means is displayed on the display means, so that the user can adjust the adjustable value displayed on the display means. In particular, the adjusting means and the setting means are disposed on the same wall of the box casing, so that the user is prevented from erroneously operating these means.
The processing means processes the photoelectric signal to detect the object within a specified region of acceptable positions in the field of detection. The result of the detection is indicated by indication means disposed on one of the walls, except the first and the second wall. Disposing the indication means on the wall on which the selecting means, fixing means or setting means is located enables the user to operate the selecting means while viewing information relating the detection indicated by the indication means.
The photoelectric switch device may further comprise selection means disposed on the second wall for selecting a desired one of a plurality of values relating to the processing of the photoelectric signal that is to be displayed on the display means and adjusting means disposed on one of the walls, except the first and second wall, for adjusting an adjustable value that is to be displayed on the display means through the processing means. The display means is capable of displaying the values relating to the processing of the photoelectric signal. In this instance, the display means changeably displays a plurality of values relating to the processing of the photoelectric signal. The user can select a desired one of the values that is to be displayed on the display means and adjust the value on the display means through the processing means. In particular, the adjusting means and the selecting means are disposed on different walls of the box casing, so that the user is prevented from erroneously operating these means. Furthermore, the display means and the selecting means are disposed on the same wall of the box casing, so that the user is able to select a desired value that is to be displayed on the display means while viewing it on the display means, which is always desirable for precisely selecting a value.
The photoelectric switch device may further comprise adjusting means disposed on one of the walls, except the first and the second wall, of the box casing for adjusting an adjustable value relating to the processing of the photoelectric signal thereon and necessary for detecting an object within a specified region of acceptable positions in the field of detection that is displayed on the display means and fixing means disposed on the second wall for fixing the adjusted value as a value relating to the processing of the photoelectric signal. In this instance, an adjustable value relating to the processing of the photoelectric signal thereon and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection is displayed on the display means. The user can adjust the adjustable value displayed on the display means and fix the adjusted value as a value relating to the processing of the photoelectric signal.
The photoelectric switch device may further comprise setting means disposed on the second wall for setting an adjustable value generated from the processing of the photoelectric signal and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection as a value relating to the processing of the photoelectric signal and adjusting means disposed on one of the walls, except the first and the second wall, for adjusting the adjustable value that is set up by the setting means and displayed on the display means. In this instance, the user can set up an adjustable value generated from the processing of the photoelectric signal and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection as a value relating to the processing of the photoelectric signal. The adjustable value that is set up is displayed on the display means. The user can adjust the adjustable value displayed on the display means by the adjusting means. In particular, the adjusting means and the setting means are disposed On different walls of the box casing, so that the user is prevented from erroneously operating these means. Furthermore, the display means and the setting means are disposed on the same wall of the box casing, so that the user can set up a value while viewing it on the display means, which is always desirable for precisely setting the value.
The photoelectric switch device may further comprises light emitting means for emitting light and optical means disposed on the first wall for directing the light toward the specified field of detection. The light emitting means and the display means are disposed on different walls of the box casing, so that, even though the box casing is miniaturized, sufficient areas for installation of the optical means and display means are certainly provided.
According to still another aspect of the present invention, the photoelectric switch device for detecting an object within a field of detection on the basis of a position of the object which is found on the basis of values of light that is reflected by the object. The photoelectric switch device comprises a generally rectangular-parallelepiped box casing defined by a plurality of walls including at least first and second walls adjacent to each other; photoelectric means for receiving light reflected by an object in the field of detection and providing a photoelectric signal having a level according to a value relating to the light representative of a position of the object relative to the photoelectric means installed in the generally rectangular-parallelepiped box casing; optical means disposed on the first wall of the generally rectangular-parallelepiped box casing for directing the reflected light to the photoelectric element; and display means disposed on the second wall of the generally rectangular-parallelepiped box casing for displaying a value generated on the basis of the photoelectric signal. In this instance, light rays from the field of detection are directed to the photoelectric means through the optical means and transformed into a photoelectric signal. Values generated on the basis of the photoelectric signal are displayed on the display means. The optical means and the display means are disposed on opposite walls of the box casing, so that, even though the box casing is miniaturized, sufficient areas for installation of the optical means and display means can be still attained. In consequence, the user can easily and precisely recognize a value relating to the processing of the photoelectric signal while viewing the value. This ensures high accuracy detection of an object.
The photoelectric switch device may further comprises adjusting means disposed on the second wall for adjusting a value that is to be displayed on the display means. Disposing the display means and the adjusting means on the same wall of the box casing enables the user to easily and precisely adjust a value while viewing the value on the display means. Therefore, the value can be easily and precisely recognized.
The photoelectric switch device may further comprises selecting means disposed on one of the walls, other than the first and the second wall, for selecting a desired one of a plurality of values generated on the basis of the photoelectric signal that is to be displayed on the display means. The display means is capable of changeably displaying the plurality of values thereon. In this instance, the display means changeably displays a plurality of values generated on the basis of the photoelectric signal. The user can select a desired one of the values that is to be displayed on the display means and adjust the value on the display means. In particular, the adjusting means and the selecting means are disposed on different walls of the box casing, so that the user is prevented from erroneously operating these means.
In addition, the photoelectric switch device may comprise processing means for processing the photoelectric signal from the photoelectric means, memory means for storing data of values generated through the processing means, and fixing means disposed on one of the walls, except the first and the second wall, for fixing and storing the adjusted value as a reference value in the memory. In this instance, values generated by the processing means are stored in the memory means. Thus, the user can adjust a value displayed on the display means by the adjusting means and stores the adjusted value as a reference value in the memory means by the fixing means. In particular, the adjusting means and the fixing means are disposed on different walls of the box casing, so that the user is prevented from erroneously operating these means.
The photoelectric switch device may further comprise setting means disposed on one of the walls, except the first and the second wall, for setting an adjustable value generated on the basis of the photoelectric signal and necessary to detect the object within a specified region of acceptable positions in the field of detection as a value relating to the processing of the photoelectric signal. The display means displays the adjustable value set up by the setting means. In this instance, the user can set up an adjustable value generated on the basis of the photoelectric signal and necessary to make a detection of the object within a specified region of acceptable positions in the field of detection as a value relating to the processing of the photoelectric signal. The adjusted value is displayed on the display means, so that the user can adjust the adjustable value while viewing it on the display means. In particular, the adjusting means and the setting means are disposed on different walls of the box casing, so that the user is prevented from erroneously operating these means.
The photoelectric switch device may further comprise processing means for processing the photoelectric signal from the photoelectric means, memory means for storing data of one of a plurality of values generated from the processing of the photoelectric signal that is set up by the setting means as a reference value and data of the reference value after adjustment by the adjusting means therein. In this instance, the photoelectric signal from the photoelectric means is processed by the processing means. A desired one of values generated from the processing of the photoelectric signal that is set up is stored as a reference value in the memory means. The reference value after adjustment by the adjusting means is also stored in the memory means.